Area Forecast Discussion
Issued by NWS Los Angeles, CA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS66 KLOX 251632 AAA
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
925 AM PDT SAT OCT 25 2014

...UPDATED MARINE DISCUSSION...

.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE THROUGH THE AREA TODAY AND TONIGHT
BRINGING A SLIGHT CHANCE OF SHOWERS TO NORTHERN SECTIONS...THEN
RESIDUAL MOISTURE WILL BRING SLIGHT CHANCE OF SHOWERS ON NORTHERN
MOUNTAIN SLOPES TONIGHT INTO SUNDAY MORNING. THERE WILL BE SOME
GUSTY WINDS TONIGHT THROUGH EARLY MONDAY...PARTICULARLY IN THE SANTA
YNEZ MOUNTAINS AND THROUGH THE INTERSTATE 5 CORRIDOR. IT WILL BE
COOLER THIS WEEKEND AND EARLY NEXT WEEK. A WARMING TREND WILL BEGIN
TUESDAY...WITH ABOVE NORMAL DAYTIME TEMPERATURES FOR MUCH OF THE
REST OF THE WORK WEEK.

&&

.SHORT TERM (TODAY-MON)...

SATELLITE IMAGERY THIS MORNING SHOWS THE WEAKENING COLD FRONT
APPROACHING NORTHERN SLO COUNTY. NOT MUCH SHOWING UP ON RADAR...WITH
MOST OF THE STEADIER ECHOES UP NEAR MONTEREY. TRIMMED BACK THE
PRECIP CHANCES A LITTLE BIT ON THE CENTRAL COAST FOR TODAY AND WENT
SLIGHT CHANCE FOR MOST PLACES N OF POINT CONCEPTION. BEST CHANCE FOR
MEASURABLE RAIN WILL BE IN FAR NW SLO COUNTY ALONG THE COASTAL
SLOPES. OTHER N OF PT CONCEPTION AREAS MAY SEE SOME SPRINKLES OR A
BRIEF LIGHT SHOWER...BUT IT WILL BE HARD TO GET ANYTHING MEASURABLE.

OTHERWISE...FORECAST LOOKS TO BE IN GOOD SHAPE. AS PREVIOUSLY
MENTIONED...TEMPERATURES WILL BE DOWN ABOUT 10 DEGREES TODAY FOR
AREAS AWAY FROM THE COAST. FROM SBA COUNTY NORTH...MOSTLY
SUNNY/PARTLY CLOUDY SKIES THIS MORNING WILL BECOME MOSTLY CLOUDY
THIS AFTERNOON AS THE COLD FRONT MOVES THROUGH. FOR LA AND VENTURA
COUNTIES...EXPECTING PARTLY CLOUDY/MOSTLY SUNNY SKIES FOR MOST OF
THE DAY...WITH SOME HIGH CLOUDS MOVING THROUGH.

***FROM PREVIOUS DISCUSSION***

BEHIND THE FRONT LATER TODAY AND TONIGHT...LOW LEVEL FLOW WILL TURN
NLY...AND N-S GRADIENTS WILL INCREASE ACROSS SLO AND SBA COUNTIES
AND THROUGH THE INTERSTATE 5 CORRIDOR. EXPECT SOME GUSTY WINDS ON
THE CENTRAL COAST THIS AFTERNOON...AND THROUGH AND BELOW PASSES AND
CANYONS OF THE SANTA YNEZ RANGE AND THROUGH THE INTERSTATE 5
CORRIDOR TONIGHT/EARLY SUNDAY. IT APPEARS AS THOUGH WINDS WILL STAY
JUST BELOW ADVISORY LEVELS FOR THE MOST PART...WITH LOCAL ADVISORY
LEVEL WIND GUSTS IN THE MORE WIND PRONE LOCATIONS. THE MOIST NLY
FLOW WILL CAUSE LOW CLOUDS TO BANK UP AGAINST THE INTERIOR SLOPES OF
THE SBA COUNTY MTNS...AND THE NRN SLOPES OF THE MOUNTAINS OF VTU AND
NWRN L.A. COUNTIES LATE TONIGHT/SUN MORNING. THERE COULD BE A FEW
SHOWERS IN THESE LOCATIONS AS WELL...AND SLIGHT CHANCE POPS LOOK
GOOD. THE WRF SUGGESTS THAT THE MARINE INVERSION WILL REMAIN INTACT
ACROSS L.A. AND VTU COUNTIES...SO EXPECT A FAIR AMOUNT OF LOW CLOUDS
TONIGHT/SUN MORNING IN MOST COASTAL AND VLY AREAS. N OF PT
CONCEPTION...BETTER COOLING ALOFT SHOULD WEAKEN THE INVERSION...AND
THIS...ALONG WITH NLY GRADIENTS SHOULD ALLOW FOR LESS IN THE WAY OF
LOW CLOUDS. MAX TEMPS WILL BE DOWN A FEW MORE DEGREES IN MOST AREAS
ON SUNDAY...EXCEPT ACROSS COASTAL SECTIONS OF SLO AND SBA
COUNTIES...WHERE LITTLE CHANGE IN MAX TEMPS IS EXPECTED.

BROAD WNWLY FLOW PATTERN ALOFT WILL SET UP ACROSS THE REGION SUN
NIGHT AND MONDAY. GOOD N-S PRESSURE GRADIENTS AND SOME SUBSIDENCE
WILL PROBABLY BRING SOME ADVISORY LEVEL WINDS TO THE SANTA YNEZ
RANGE AND ADJACENT PORTIONS OF THE S COAST OF SBA COUNTY SUN
NIGHT...AND TO THE INTERSTATE 5 CORRIDOR SUN NIGHT INTO EARLY
MONDAY. THERE STILL MAY BE SOME LINGERING NIGHT THROUGH MORNING LOW
CLOUDS AND FOG SUN NIGHT/MON...MAINLY ACROSS L.A. COUNTY COASTAL
AREAS...BUT EXACTLY HOW WIDESPREAD THE CLOUDINESS WILL BE IS IN
QUESTION. WITH LITTLE CHANGE IN HEIGHTS/THICKNESSES...AND LITTLE
CHANGE IN TEMPS AT 950 MB...EXPECT MOSTLY MINOR CHANGES IN MAX
TEMPS ON MONDAY...ALTHOUGH SOME WARMING IS POSSIBLE ACROSS PORTIONS
OF SLO AND SBA COUNTIES DUE TO NLY WINDS.

.LONG TERM (TUE-FRI)...AN UPPER RIDGE WILL BEGIN TO BUILD INTO THE
REGION FROM THE ERN PACIFIC ON TUESDAY. RISING HEIGHTS AND WEAK
OFFSHORE FLOW SHOULD BRING SEVERAL DEGREES OF WARMING TO MOST
AREAS...WITH ANY NIGHT THROUGH MORNING STRATUS LIKELY LIMITED TO THE
IMMEDIATE COAST. THE UPPER RIDGE WILL AMPLIFY INTO THE REGION ON
WED...AND OFFSHORE GRADIENTS WILL INCREASE A BIT MORE. THIS SHOULD
BRING A FEW MORE DEGREES OF WARMING TO MOST AREAS...WITH TEMPS
LIKELY RISING WELL INTO THE 80S AND POSSIBLY TO NEAR 90 DEGREES
ACROSS THE WARMER LOCATIONS IN THE LOWER VLYS AND ACROSS INTERIOR
SECTIONS 0F THE COASTAL PLAIN. THE GFS BRINGS A WEAK TROUGH INTO THE
REGION ON THU...INDICATING SOME COOLING...WHILE THE EC IS SLOWER
WITH THE TROUGH...AND KEEPS TEMPS RATHER SIMILAR ON THU. GIVEN THE
TREND THIS FALL OF WARM SPELLS LINGERING LONGER THAN ANTICIPATED...
WL LEAN TOWARD THE WARMER EC MODEL FOR THU...WITH SIGNIFICANT AND
MORE WIDESPREAD COOLING FOR FRI AS THE TROUGH APPROACHES THE W
COAST. BOTH THE EC AND THE GFS SUGGEST THAT THE FIRST WIDESPREAD
RAIN EVENT OF THE SEASON MAY OCCUR NEXT FRIDAY NIGHT AND SATURDAY.
WE WILL SEE.

&&

.AVIATION...25/1120Z...

THE BASE OF THE INVERSION AT KLAX AT 0810Z WAS NEAR 800 FT. THE
INVERSION TOP WAS AT 2700 FEET WITH A TEMPERATURE OF 21 DEGREES C.

OVERALL...LOW TO MODERATE CONFIDENCE IN 12Z TAF PACKAGE.

NORTH OF POINT CONCEPTION...WEAKENING COLD FRONT WILL BRING SOME
SCATTERED LIGHT SHOWERS LATER THIS MORNING THROUGH EARLY THIS
AFTERNOON. MODERATE CONFIDENCE IN DEVELOPMENT OF MVFR CIGS IN
ASSOCIATION WITH THE LIGHT SHOWERS. BY MID-AFTERNOON...EXPECT ANY
MVFR CLOUDS TO DISSIPATE AND VFR CONDS SHOULD PREVAIL THE REMAINDER
OF THE TAF PERIOD...EXCEPT FOR KPRB WHERE MVFR CIGS MAY DEVELOP
AGAIN TONIGHT.

SOUTH OF POINT CONCEPTION...SCT-BKN IFR/MVFR DECK WILL COME IN AND
OUT OF TAF SITES THROUGH 18Z. LOW CONFIDENCE IN LOW CLOUD FORECAST
FOR TAFS THROUGH THIS MORNING. FOR THIS AFTERNOON AND EVENING...VFR
CONDS SHOULD PREVAIL. HOWEVER...MODERATE CONFIDENCE IN THE RETURN OF
SOME MVFR/IFR CIGS TO LAX BASIN TAF SITES AFTER 06Z.

KLAX...LOW CONFIDENCE IN 12Z TAF. SCT-BKN IFR CLOUD DECK WILL
CONTINUE THROUGH ABOUT 18Z THIS MORNING...RESULTING IN LOW
CONFIDENCE CLOUD FORECAST. FOR TONIGHT...MODERATE CONFIDENCE IN
RETURN OF STRATUS...BUT LOW CONFIDENCE IN FLIGHT CATEGORY AND TIMING
OF RETURN.

KBUR...LOW CONFIDENCE IN 12Z TAF. SCT-BKN IFR CLOUD DECK WILL
CONTINUE THROUGH ABOUT 18Z THIS MORNING...RESULTING IN LOW
CONFIDENCE CLOUD FORECAST. FOR TONIGHT...MODERATE CONFIDENCE IN
RETURN OF STRATUS...BUT LOW CONFIDENCE IN FLIGHT CATEGORY AND TIMING
OF RETURN.

&&

.MARINE...25/900 AM...

FOR THE OUTER WATERS...NORTHWEST WINDS WILL INCREASE BEHIND A WEAK
FRONTAL PASSAGE THIS EVENING...WITH HIGH CONFIDENCE THAT WINDS WILL
INCREASE TO AT LEAST SMALL CRAFT ADVISORY LEVEL THIS EVENING AND
CONTINUING THROUGH MONDAY. AS THE NORTHWEST FLOW INCREASES ON SUNDAY
GALE FORCE WINDS WILL BE POSSIBLE. WILL LIKELY ISSUE A GALE WARNING
FOR LATE SUNDAY AFTERNOON AND NIGHT...WITH GUSTS 35 TO 40 KNOTS.

FOR THE INNER WATERS...MODERATE CONFIDENCE IN THE DEVELOPMENT OF
SMALL CRAFT ADVISORY-LEVEL WINDS ACROSS THE WESTERN HALF OF THE
SANTA BARBARA CHANNEL SUNDAY THROUGH MONDAY. ELSEWHERE ACROSS THE
INNER WATERS...WINDS ARE ANTICIPATED TO REMAIN BELOW SMALL CRAFT
LEVELS. HOWEVER...THERE IS A SMALL CHANCE THAT GUSTS TO 25 KNOTS
WILL AFFECT THE WESTERN PORTIONS OF PZZ655 AND 645.

A LARGE WEST SWELL AT MODERATE PERIODS (13 SECONDS) WILL MOVE INTO
THE COASTAL WATERS THIS EVENING THROUGH SUNDAY NIGHT. EXPECT SEAS OF
10+ FEET TO IMPACT THE NEAR-SHORE WATERS NORTH OF POINT SAL. A SCA
FOR HAZARDOUS SEAS IS IN EFFECT FOR THIS AREA.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
GALE WATCH (SEE LAXMWWLOX).
HIGH SURF ADVISORY (SEE LAXCFWLOX).
BEACH HAZARDS STATEMENT (SEE LAXCFWLOX).

&&

$$

PUBLIC...SS/DB
AVIATION/MARINE...RAT/SMITH
SYNOPSIS...DB

WWW.WEATHER.GOV/LOSANGELES








USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.